1 files changed, 143 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c
new file mode 100644
index 000000000..8d7547540
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <pthread.h>
+#include <sched.h>
+#include <sys/socket.h>
+#include <test_progs.h>
+#include "test_perf_buffer.skel.h"
+#include "bpf/libbpf_internal.h"
+
+static int duration;
+
+/* AddressSanitizer sometimes crashes due to data dereference below, due to
+ * this being mmap()'ed memory. Disable instrumentation with
+ * no_sanitize_address attribute
+ */
+__attribute__((no_sanitize_address))
+static void on_sample(void *ctx, int cpu, void *data, __u32 size)
+{
+	int cpu_data = *(int *)data, duration = 0;
+	cpu_set_t *cpu_seen = ctx;
+
+	if (cpu_data != cpu)
+		CHECK(cpu_data != cpu, "check_cpu_data",
+		      "cpu_data %d != cpu %d\n", cpu_data, cpu);
+
+	CPU_SET(cpu, cpu_seen);
+}
+
+int trigger_on_cpu(int cpu)
+{
+	cpu_set_t cpu_set;
+	int err;
+
+	CPU_ZERO(&cpu_set);
+	CPU_SET(cpu, &cpu_set);
+
+	err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set);
+	if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n", cpu, err))
+		return err;
+
+	usleep(1);
+
+	return 0;
+}
+
+void test_perf_buffer(void)
+{
+	int err, on_len, nr_on_cpus = 0, nr_cpus, i;
+	struct perf_buffer_opts pb_opts = {};
+	struct test_perf_buffer *skel;
+	cpu_set_t cpu_seen;
+	struct perf_buffer *pb;
+	int last_fd = -1, fd;
+	bool *online;
+
+	nr_cpus = libbpf_num_possible_cpus();
+	if (CHECK(nr_cpus < 0, "nr_cpus", "err %d\n", nr_cpus))
+		return;
+
+	err = parse_cpu_mask_file("/sys/devices/system/cpu/online",
+				  &online, &on_len);
+	if (CHECK(err, "nr_on_cpus", "err %d\n", err))
+		return;
+
+	for (i = 0; i < on_len; i++)
+		if (online[i])
+			nr_on_cpus++;
+
+	/* load program */
+	skel = test_perf_buffer__open_and_load();
+	if (CHECK(!skel, "skel_load", "skeleton open/load failed\n"))
+		goto out_close;
+
+	/* attach probe */
+	err = test_perf_buffer__attach(skel);
+	if (CHECK(err, "attach_kprobe", "err %d\n", err))
+		goto out_close;
+
+	/* set up perf buffer */
+	pb_opts.sample_cb = on_sample;
+	pb_opts.ctx = &cpu_seen;
+	pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1, &pb_opts);
+	if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
+		goto out_close;
+
+	CHECK(perf_buffer__epoll_fd(pb) < 0, "epoll_fd",
+	      "bad fd: %d\n", perf_buffer__epoll_fd(pb));
+
+	/* trigger kprobe on every CPU */
+	CPU_ZERO(&cpu_seen);
+	for (i = 0; i < nr_cpus; i++) {
+		if (i >= on_len || !online[i]) {
+			printf("skipping offline CPU #%d\n", i);
+			continue;
+		}
+
+		if (trigger_on_cpu(i))
+			goto out_close;
+	}
+
+	/* read perf buffer */
+	err = perf_buffer__poll(pb, 100);
+	if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
+		goto out_free_pb;
+
+	if (CHECK(CPU_COUNT(&cpu_seen) != nr_on_cpus, "seen_cpu_cnt",
+		  "expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen)))
+		goto out_free_pb;
+
+	if (CHECK(perf_buffer__buffer_cnt(pb) != nr_on_cpus, "buf_cnt",
+		  "got %zu, expected %d\n", perf_buffer__buffer_cnt(pb), nr_on_cpus))
+		goto out_close;
+
+	for (i = 0; i < nr_cpus; i++) {
+		if (i >= on_len || !online[i])
+			continue;
+
+		fd = perf_buffer__buffer_fd(pb, i);
+		CHECK(fd < 0 || last_fd == fd, "fd_check", "last fd %d == fd %d\n", last_fd, fd);
+		last_fd = fd;
+
+		err = perf_buffer__consume_buffer(pb, i);
+		if (CHECK(err, "drain_buf", "cpu %d, err %d\n", i, err))
+			goto out_close;
+
+		CPU_CLR(i, &cpu_seen);
+		if (trigger_on_cpu(i))
+			goto out_close;
+
+		err = perf_buffer__consume_buffer(pb, i);
+		if (CHECK(err, "consume_buf", "cpu %d, err %d\n", i, err))
+			goto out_close;
+
+		if (CHECK(!CPU_ISSET(i, &cpu_seen), "cpu_seen", "cpu %d not seen\n", i))
+			goto out_close;
+	}
+
+out_free_pb:
+	perf_buffer__free(pb);
+out_close:
+	test_perf_buffer__destroy(skel);
+	free(online);
+}